Apparatus for the recovery or precious metals.



I?. OERIG.

APPARATUS WJH THE RECVERY OFPRECOUS METALS.

APPLICATION FILED IIILY 27.19II.

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3 SHEETS-SHEET l.

E. E. KOERLNG.

lAPPARATUS FOR THE RECOVERY of PRECIOUS METALS.

` APPLICATION FILED JULY 27,194. i

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3 SHEETS-SHEET 2.

APPARATUS SSHEETS-SHEET 3 FILED JULY 27. l'wl,

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I BRUNO lIR., KOERING, OF DETROIT. MICHIGAN', ASSIGNOR TO KOERING- CYANIDING PROCESS COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF ARIZONA.

APPARATUS FOR THE RECOVERY OF PRECIOUS METALS.

To alf whom it lmay concern:

Be it known that I, BRUNO R. KOERING, a citizen of the United States, residing at Detroit, in the County of `Wayne and State of Michigan, have invented certain new and useful Improvements in Apparatus for the Recovery of Precious Metals,l of which the following is a specification.

My invention relates to apparatus forv` the recovery of precious metals, 'and refers particularly to the chemical treatment of the ores of gold and silver.

It is well known that after ores of the precious metals, such as gold and silver, have beennely crushed the metals are recovered from the ores by a chemical treatmente-in the case of gold, by cyaniding or chlorination, and in the case ofsilver, by hypO-Sulting.

As heretofore carried out, the' process and apparatus for chemically treating the ores for the purpose'just described have been cumbersome, inefficient, and slow in action. The principal operations have consisted, irst, in agitating the .ore with the solution in order to obtain thorough percolation'by the solution to cause it to dissolve the precious metals present; second, the separation of the solution Vfrom the pulp and slimes resulting from treatment of the ore; third, the filtration of the metal bearing solution in order t0 obtain it in a clear condition preparatory to precipitation -of the precious metals; and, fourth, washing of -the pulp and slimes in order to free them from all traces of the metal bearing solution. These operations have required large and .:pensive tanks and various complicated apparatus for agitating, washing and filtering. As an example of the complication of the treatment it may be mentioned that it has been customary in the case of wet, crushed ores to first expel a certain percentage of moisture in a machine called a thickener, and in m'any cases where fine grinding has been used and the ore contains a considerable portion of clay the so-called slimes thus formed have been separated on a slime table from the silicious residue, -which is the pulp free from slimes.

It is the object of my invention to simplify the process of extracting the metal from the ores by eliminating the various complicated apparatus heretofore used and conducting .the entire extracting operation in a single Speccation of Letters Patent.

the slimes or transferring the ore or solution to various tanks and other apparatus for conducting the various steps of the eixtraction process. After the extraction process has been completely carried out in my improved apparatus, the pulp and slimes may be quickly sluiced out of the drum and the latter is ready for a new charge of ore. Not only is my apparatus economicalfin its first cost of installation and in its operation, but it also saves much time in the carrying out of the extracting process.

These and other advantages ofmy invention will be more readily understood by reference to the accompanying drawings, which represent a preferred form of apparatus for carrying out my invention,` and in which- Figure 1 is a 'diagrammatic side elevation of a plant in which my apparatus and process are used; Fig. 2 is a diagrammatic plan of the plant shown in Fig. 1; Fig. 3 is a side elevation and partial longitudinal section showing my improved extraction drum; Fig. -i is an end elevation of the drum shown in Fig.l 3; Fig. 5 is a transverse section taken on the' line 5-5of Fig. 3; and Fig. G is a fragmentary side elevation of the extraction drum, showing the pipes for discharging the solution during rotation of the drum.

In order that the purpose of my invention may be more clearly understood, I will first describe a typical plant, as shown in Figs. 1 and 2. The ore from the mine is brought to the plant on a car 10, and this ore is then placed in a bin 11 by dumping through the hopper 12. rlhe mine-run ore in the bin 11 is then fed to the crusher 13, being admitted from the bin 11 through the gate 1li. rEhe crushed ore 15 vis then stored in the bin 16. The stock solution tank 17 may be located on the same floor with the crusher 13. mill 1S by means of the automatic feeder 19. From the mill ISthe ore passes to the pebble mill 20, the function of the mill 18 The crushedore 16a is supplied to the' Patented Dec. 14, 1915.

Application filed July 27, 1914. Serial No. 853,350.

'or otherwise to the solution tank 22, from which the metal bearing solution is supplied to the precipitation tanks 2,3 through' the pipes 24. The precipitation tanks 23 are of special construction, but they form no part of the present invention. rAfter the metals have been precipitated from the so .lution in the tanks 23, this solution is then 'conveyed to' the sump tank 25 through the pipe 26,- after which the 'solution is returned to the stock solution tank 17 through the pipe 27. In order to operate the crusher 13 and the mills 18 and 2O andthe extraction drum 21, an engine 28 operated from the 'boiler 29 is provided. v c

Having thus described the applicability of my invention in connection with the complete operation of the recovery of precious metals from their ores, will now pass to a detailed description of the extraction ydrum used in my invention.

The extraction drum 21 consists of a circular outer shell,30 ofsteel or other suitable material, on which are mounted the gears V31 near each end ofthe drum. Im- .uzediately' adjacent to each of the gears 31 aio the drum tracks 32, which engage the idlers l33, these idlers thereby serving to support the drum. Each of the gears 31 is 4engaged by a pinion 34 which is mounted on the main driving shaft 35 carried in the bearings 36, 36 and 37, 37. The driving shaft 35 is rotated from any suitable source of power, as,4 for example, from the 'engine 28 shown in Fig. 2. On rotation of the driving. shaft 35 it will bef evident that the extraction ldrum 21 is rotated .on its longitudinal axis ,by reason of the engagement of the pinions 34 with the gears 31.

Separated from the outer shell 30 by an .annular space is the inner.l perforated shell 38, whichis held in position by the longitudinally Hdisposed beams 39 and 41 which form division walls of the solution compartment 40 located between the4 outer shelf-*30 and the inner Aperforated shell 38. 'As clearly shown in Fig. 5, the' division ,l

walls -39 are provided with passages 40, preferablyadjacent to the outer shell 30 for a'purpsewhich will-presently be described. The `division wallsY 41. are ynot' provided .with suchaj passage 40", Ybut a by-pass pipe 42,`

leads from the two sides of the division wall 41, shown in lower position in Fig. 5. `The drain pipe-42*I leads from'the by-pass pipe 42, and at the point of junction of the pipes 42 and 42l is provided the by-pass valve 43,

so tha't on opening of this valve, liquid may pass into drain pipe r42a from both sides of ,the division wall 41, while on closing valve 43 communication between opposite sides of division wall 41 and also with the pipe 42 is interrupted.

Immediately inside ofthe perforated inner shell 38 Ais placed the retaining. screen 44. Inside of this retaining screen in turn is the filter cloth 45, and inside of the filter cloth is the spreading screen 46. V The object of the retaining screen' 44 and thespreading screen 46 is to hold the filter cloth securely in position. Theretaining screen 44,

mately half way 'around the inner` surface the filter cloth 45, and the spreading screen -46 are preferably made each in two pieces, l.each of these twoJpieces extending approxiof the inner shell 38. The spacing angles 47 fastenedtothe inner `shell 38' by the bolts or rivets 48` are vlocated diametrically Opposite to each other. The edges of the retaining screen 44 terminate at or near the outer edges of these spacing angles 47. The edges of the filter cloth 45 are held in position between the inner surfaces of the' spacing angles 47 and the clamping anglesv 49. The

latter are held in position by means ofthe clamping rods 50, each. of which has on its outer end theengaging member 51. 'Between each pair of clamping rods 50 is the first loosening the sleeve nut 52 anffithen re:

moving the clamping ro'ds 50.

l The 'extraction drum 21 is closed at its ends by the head lates 54 and 55, which are held in positionV y' means of suitable bolts- 56 andV 57.A The head plate 54 is 'prgvided with twoaapertures, namely, the orecharging hole 58 and the `sluici,ng hole 59.` The ore charging hole 58 is normally closed'by the cover 60 held in position by the bolt 6-1 and the sluicing hole 59 is closed by the co'ver '62 heldin vposition by the bolt 63. The head plate 54 has passin through it the. solution pipe. 64 .'withf. th valve 65 therein.

As shown inV Figs. 3, 5 and 6, thepipes 65 may be provided leading from the solu-fv` tion 'chamber 40 at the sameend 'of .the'f'exf traction drum as thaton" which;` `the head plate 54 is located.` These pipes 65'un`ite messes ber 40.

The head plate 55 has passing through its i center a pipe 66 provided with theva`lve 67.

Connectedv with the pipe 66. is a pipe 68, the sleeve 69 being placed between the pipes 66 and 68 so that a connection is aorded between these two pipes, while it is unnecessary to disconnect them on rotation-of the extraction drum 2l with which the pipe G6 rotates. yThe pipe 68 is connectedwith the pipes 70 and 7l, in which are the valves 72 and 73, respectively. The pipe 70 communicates with a suitable source of high pressure air, while the pipe 71 connects with a source of water. If desired, a suitable valved pipe connecting with a source of steam may also be connected with the pipe G8.

The head plate .55 has the aperture 74 therein witlrwhich the pulp and slimedischarge valve 75 is connected. The valve 75,

as clearly shown in Fig. 4l, is preferably af gate valve, and is operated by the handle 7-6. Leading from the outer Shell 30 are the solution discharge pipes 77 and 77a (preferably two in number), controlled by the valves 78 and 78a. lVhen two discharge Mpipes, as 7-7 and 77a, are employed, they are located on opposite sides of the division wall 4l with which the by-pass 42 is associated, 'as clearly shown in Fig. 5. The head'plate 55 is also providedv with the air check valves 79 and 79a, the purpose of which will be hereafter described.

Having thus described the apparatus used in connection with my invention, the method of operation may now be readilyunderstood.'

For the'sake of simplicity, l will describe my process as used in connection with the cyaniding of gold ores, it being understood that other solutions for the extraction of other metals may be used without departing from the spirit of my invention. After the ore has been finely crushed, it is introduced into the leaching chamber 80 of the extraction drum through the ore charging hole 5S, the cover 60 being removed for the pur-f pose. This cover is then replaced. If .the ore has been crushed wet', the drum is rotated and stopped with the by-pass valve 43 in its lowermost position. During this rotation water has passed from the ore through the filter cloth 45. Air is now introduced' through the valve 79 and xserves'l'to clean the filter cloth l5 on its passage from the solution chamber -LLO to the leaching chamber 80. rThe by-pass valve 43 (which is normally closed) is opened in order to' allow all of the wateraccurnulating in the solution compartment 40 to drain oli' through pipes l2 and 42a, this action being facilitated' by the pressure of air within ing chamber.

the extraction drum. By ythis method of filtering the thickening operation is greatly facilitated and'the separation of the ore into silicious pulp and slimes is entirely avoided. If the ore has been crushed dry, or in the case'of wet ores after the filtering just de- {scribed has taken place, the cyanid solution is next introduced. This is. accomplished by opening the valve 65 and allowing the cyanid to fiow into the central or leaching chamber contained within the inner shell 3S. If preferred, the cyanid solu- `tion may be introduced through the ore ore a concentrated cyanid solution through pipe 6l and valve 65, so that when this concentrated solution is diluted by the known amount of water introduced with the ore pulp, a standard cyanid solution of correct strength is formed. A sufficient amount of cyanid is introduced so that the leaching chamber is nearly filled with the ore and solution. The solution is preferably heated before it is introduced, inasmuch as the extraction process is thereby considerably aided. All valves and openings of the eX- traction drum being now closed, the latter is rot-ated by means of the, main driving shaft 35. By the constanttumbling of the ore with the cyanid solution the latter is caused to percolate thoroughly through the ore.I After a thorough .mixture of the ore The drum is then allowed 4to revolve slowly for a period of from two to eight hours, depending on the character of the ore. A5 the drum rotates the solution passes through the filter cloth -l5 into the solution compartment -lOL The by-pass valve beingclosed,

the division walls ll serve to lift the filtered solution to the upper portion of the drum returns through the filter cloth to the leach- This operation is repeated over and over again until the gold contained in the ore passes into the solution.

cient length of time' so that all gold has been lVhen` .this operatlon has been conducted a suffin 'as the latter rotates, and the solution again with the valve 78 in its lowermost position.

The solution which is at that time within clean the filter cloth by forcing air through it and by causing some of the solution from compartment 40 to flow into the leaching chamber 80. The drum is now revolved so as to bring the discharge valve 78L toits lowerniost position. The remaining clear gold' bearing solution is then withdrawn v from the leaching chamber 80 and the solution compartment 40 through the pipe 77 by opening' the valve 7 8a. At the same time air is introduced into the solution compartment 40 through the air check valve 79a in order, as before, to aid the expulsion of the solution, and to clean the filter cloth 45.

The gold bearing cyanid solution is carried to the solution tank 22, and the gold lis subsequently precipitated from it; but this portion of the process forms no part of the present invention. If desired, the gold bearing solution'may be withdrawn from the solution chamber 40 during rotation of the extraction drum by ocning the valve 65e thereby causing the cyanid solution'to pass through the pipes 65a into the solution discharge pipe'65". After the cyanid solution has been expelled from the solution compartment 40, the valves 78 and 78, o r 65 as the case may be, are closed, and water is introduced into the leaching chambertby opening the valves 73 and 67, the valve 72 meanwhile being closed. At the same time the extraction drum 21 is revolved in order to make the Washingv process complete'. Another method of introducing the water 1s through valve 65, after Which thedrum is` revolved. The water serves to remove from the pulp and slimes contained within the,

leaching chamber all of the remaining cyanid solution, which passes through the filter cloth .45 into the solution compartment, and onstopping the drumthis solution is removed through the discharge pipes 77 and 77* inexactly the same manner that the original cyanid. solution was removed as Vabove described, the filter cloth being cleaned meantime by the action of the air introduced through the valves 79 and 79a.

This solution may also be removed through the pipes 'and 65c during rotation o f the drum, as described above.y The drum is then revolved so that the by-pass valve 43 is? brought toits lowermost position. valve 43 is then opened and the remainder ofthe-'solution in the compartment 40 is The drawn off through the pipes 42 and ,422` This Washing water is then taken to the solution tank 22" and added to the metal bearing solution which has previously been placed' in said tank. By means of the washing process which has just been described,

the leachingy chamber 'are carried through the opening 74 past the discharge valve 75, and these tailings are then carried by a belt conveyer or otherwise to a suitable dump or other place'v of disposal. Any Water accumulating in the solution compartment flt drains off through the pipes 42 and 42a.

I have describedmy invention as particularly used in connection with thev cyaniding of gold ores, but it will be understood that the chlorination process may be used With equal facility. In the latter case the chloriii gas is introduced into the leaching chamber through the pipe 66, or, if preferred, the acid and chlorid of lime are placed in the leaching chamber so that the chlorin gas is l 'generated therein. When the 'chlorination process is used, all metal surfaces inside of the drum are enameled in order to prevent the steel from being attacked by the chlorin' gas. If desired, in this rocess the interior parts may also be ma e of wood, or the metal parts may treated with asphaltum.

In the case' .silver ores the hypo-sulfite solution isu'sed instead of the cyanid or chlorination 'process, but the sequence of steps Iconstituting my distinctive process and the apparatus used are the same as previusly described.

It'will be apparentl to those skilled in the art that many changes may be made' in the details of the method of operation and in the apparatus which'Iv have described 'without vdeparting from the spirit or scope of my g invention.

What I claim is: A 1. In an apparatus for extracting metals from-ores, the combination ofa drum, means iso rial in said leaching chamber accumulating on' said ltering means. A

2. ln an apparatus for extracting metal from ores,the combination of a cylindrical drum having end plates tlerefor, one of said end plates having an ore charging aperture therein,vmeans for closing said aperture, a perforated shell minted concentrcally with the olitershell of said drum whereby a solution chamber is formed vbetween the outer shell of said drinn and said inner shell and a leaching chamber is formed within said ber, one of said endplates having an aperture for charging ore into one of said cham.-

bers and means for closing said aperture,

inner shell, a filter cloth' fastened. to `saidperforated shell, a division wall extending L'longitudinally through said solution. chamber, means for introducing Huid into said vleaching chambe'r,.a valve'd solution outlet from 'said' 4solution chamber, a valved discharge outlet from saidleaching'chamber,

means for introducing air into said solution chamber, and means for rotating said drum.

3. In apparatus of the class described, the

l 4 combination of a rotatable cylindrical drum having end plates therefor, filtering means spaced inwardly from the periphery of said means forintroducing a metal-extracting: fluid' intosaid drum to enter said ore-receiving chamber, and means for introducing a non-extracting fluid into the other of said chambers.

v5. ln apparatus of the class described, the

combination of a rotatable cylindrical drum' having end platesl therefor, ltering means spaced inwardly from the' periphery of said drum, whereby it is divided into an inner leaching .chamber and an outer solution chamber, oneof said end plates having an aperture lfor charging ore into said leaching chamber and means for closing said aperh ture, means for introducing a metal-eXtracting Huid into 4said leaching chamber, an'd means for introducing a non-extracting iiuid under pressure into saidsolution chamber.

6. ln apparatus of the classdescribedgqthe combination of a rotatable cylindricaldrum perforated metal shell spaced inwardly from said outer shell, whereby an inner chamber and an outer annular chamber are formed, a filtering medium carried by said inner shell, means for closing the ends of said an' nular chamber', and removable heads for closing the ends of said inner chamber.

drum, whereby 'the latter is divided into an inner chamber and an outer annular chamln witness whereof, I hereunto subscribe myv name this 24th day of July, A. D. 1914:

BRUNO R. KOERING. Witnesses:

CHAs. P. BENOIT, Jr., H. M. LIVINGSTON.

60 i having anouter metal shell arid an'inner 

